Device for delivering harness elements of a power loom

ABSTRACT

A device is used for the transfer of harness elements ( 21 ) from a conveying member ( 21 ) in a drawing-in machine for warp yarns onto carrying members of a weaving machine, that has an ejector for removing the harness elements from the conveying member. In order to provide a device in which the carrying members are aligned as exactly as possible at the moment when the harness elements are transferred onto them, there is provided a guide roller for the harness elements which is mounted rotatably about an axis and which has guides for the carrying member which guide the carrying members in two orthogonal directions.

BACKGROUND OF THE INVENTION

The invention relates to a device for the transfer of harness elementsfrom a conveying member in a drawing-in machine for warp yarns ontocarrying members of a weaving machine, with an ejector for removing theharness elements from the conveying member.

EP 500 848 has already disclosed such a device, in which the carryingmembers, designed as carrying rails, have an oblique entry flankdirected downwards. Ejectors push the harness elements from carryingpins of a conveying member up onto these entry flanks, so that theharness elements slide along these entry flanks onto the carrying rails.The carrying rails are retained or supported against gravity by holdingbolts which are capable of being moved in and out and which are fastenedto a transport system. In their moved-in position, these holding boltsposition the carrying rails. The holding bolts are moved out in order toallow the harness elements to pass at the relevant point.

A disadvantage of the known device mentioned is to be seen in that, inorder to allow the harness elements to pass, the guidance or support ofthe carrying rails is temporarily removed precisely when the harnesselement passes over from the carrying pins of the conveying member ontothe carrying rail. This puts exact alignment of the carrying pins andcarrying rails at risk. This adverse circumstance can, admittedly, beeased by arranging the said guide of the carrying rails as far aspossible from the conveying member, but, even then, the exact alignmentof the carrying pins and carrying rails is impaired.

SUMMARY OF THE INVENTION

The invention, provides a device in which the carrying members arealigned as exactly as possible at the moment when the harness elementsare transferred onto them.

This is achieved in that the carrying members or carrying rails areguided by a guide roller which is arranged very near the end of thecarrying member at the conveying member and which has guides for thecarrying member which guide the latter in two orthogonal directions,that is to say laterally and in the direction of gravity, during thetransfer of the harness elements. The guide roller has a recess which,starting from the circumference, extends towards the axis and serves, onthe one hand, for providing space for the lock-transfer of the end eyesof the harness elements and, on the other hand, for providing anengagement surface for the forward movement of the harness elements onthe carrying member by means of the guide roller. In this case, theguide roller, together with the recess, forms a transfer lock for theharness elements.

The advantages achieved by means of the invention are to be seen, inparticular, in that the carrying member is guided in an exact anddefined manner at the moment when the harness elements are transferredfrom the conveying member, guidance for the lock-transfer of the harnesselements being partially cancelled only when the harness element hasalready been taken up by the carrying member. In this case, the carryingmembers are always guided laterally by the guide roller, whatever theposition of the latter. Another advantage is to be seen in that theguide roller executes a simple rotational movement and, at the sametime, propels the harness elements some distance forwards. The guideroller may be designed for any number of adjacent carrying members.While a single harness element is being propelled forwards by the guideroller, the latter additionally holds back harness elements which havealready been transported, so that these cannot be pushed towards theconveying member again.

BRIEF DESCRIPTION OF THE DRAWING

The invention is explained in more detail below by means of an exampleand with reference to the accompanying figures:

FIG. 1 is a schematic sectional view of the device according to theinvention.

FIG. 2 shows part of the device on an enlarged scale.

FIG. 3 shows a view of the device in a first operating phase, the saidview having been pivoted through 90° in relation to FIG. 1.

FIGS. 4 and 5 show the device in two further operating phases.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a section through part of a guide roller 1 for a pluralityof carrying members 2, 3, 4, which are arranged next to one another atequal intervals. The guide roller 1 is mounted on a shaft 5 rotatablyabout an axis 6 in a way not illustrated in any more detail, but knownper se, and is connected to a drive 7. The guide roller 1 has lateralguides 8, 9 for guiding the carrying member 4 in the direction of anarrow 10 and guides 11 for guidance in the direction of an arrow 12, andtherefore for guidance in two orthogonal directions. The guides 8, 9 areinterrupted or widened in the region of a recess 13 and therefore do notform a closed circular ring. A harness element 14, which is located onthe carrying member 4, is depicted in the recess 13. A region delimitedby an arc of a circle 15 shows a section through the guide roller 1,this section in turn, being located in the region of the guides 8, 9,11, although, in this case, the carrying member 2, which is guided bythese guides 8, 9, 11, is depicted.

FIG. 2 once again shows, on an enlarged scale, the carrying member 2together with the guides 8, 9, 11 of the guide roller 1.

FIG. 3 shows, from another viewing angle, the arrangement of the guiderollers in or in front of a drawing-in machine for warp yarns. Since theharness elements 16, illustrated diagrammatically here, have an eye 17,18 at the top and bottom in each case, two carrying rails 19, 20 arealso provided as carrying member. The drawing-in machine has, as part ofa conveying member 21, 21′ for each harness element, two holding bolts22, 23, a plurality of which are arranged next to one another, forexample, on a rotating chain in each case, as is known, for example,from EP 500 848 already mentioned. Moreover, the drawing-in machinepreferably has two ejectors 24, 25, which are each illustrated here inthe initial position 26, 27 and in the end position 28, 29. Theseejectors are capable of executing a lifting movement out of the initialposition into the end position. However, such ejectors 24, 25 are knownper se and therefore the way in which they are driven is not describedin any more detail either. A guide roller 30, 31 is also provided foreach carrying rail 19, 20. The said guide rollers are illustrated insection here, the section running in a plane which is illustrated inFIG. 1 by a broken line 32 and, in principle, passes through the centerof the harness elements. Thus, the recess 33, 33′, which corresponds tothe recess 13 (FIG. 1) and which, starting from the circumference 34,34′, extends towards the axis 35, is also rendered clearly visible. Therecess 33 causes the guide 36, corresponding to the guide 11 (FIG. 1),to extend approximately over three quarters of the circumference. Thisproportion is greater for the lateral guides 37, 38, which correspond tothe guides 8, 9 (FIG. 1). The guide roller is arranged very near the end46, 47 of the carrying rails 19, 20 or of the carrying member and so asto be adjacent to the conveying member 21, 21′.

FIG. 4 again shows the same elements as FIG. 3. These elements aretherefore also given the same reference symbols. However, the guiderollers 30, 31 and the harness element 16 have assumed a differentposition. The harness element 16 has been grasped by guide surfaces 39,40 in the recesses 33, 33′ and moved on the carrying rails 19, 20. Theejectors 24, 25 are still in their end positions 28, 29.

FIG. 5 shows, yet again, the same elements as FIG. 3. Here, the harnesselement 16 is illustrated as having been transported even further.

The device operates as follows: A harness element 16, such as, forexample, a heald or drop wire, is guided in a way known per se, on twoholding bolts 22, 23, in front of the carrying rails 19, 20 bysynchronously rotating conveying members 21, 21′. The ejectors 24, 25then move out of the initial positions 26, 27 into the end positions 28,29, the end eyes 17, 18 of the harness element 16 being stripped fromthe holding bolts 22, 23 in the direction of an arrow 45 and beingpushed onto the carrying rails 19, 20. During this time, the carryingrails 19, 20 are guided laterally by the guides 37, 38, 37′ 38′ andvertically by the guide 36, 36′. The harness element 16 is then graspedby the guide rollers 30, 31, which rotate in the direction of the arrows41, 42. Since the channel defined by the guides 8, 9, 11 (FIG. 1) and36, 37, 38 and 36′, 37′ 38′ is as narrow as a carrying rail 19, 20, butnarrower than an end eye 17, 18, a boundary 43, 44 of the recess 33, 33′forms a guide surface 39, 40 (FIG. 4), along which the end eyes 17, 18slide and, at the same time, are moved further on the carrying rail 19,20. In this case, the guidance of the carrying rails 19, 20 by theguides 36, 36′ is lost for a short time in the region of the position asshown in FIG. 4, but this is not a disadvantage, since the transfer ofthe harness element 16 onto the carrying rails 19, 20 has already takenplace. The lateral guidance of the carrying rails by the guides 8, 9(FIG. 1) and 37, 38 and 37′, 38′ is always maintained. In the positionshown in FIG. 5, guidance is once again effective on all sides. Fromthen on, the guide roller 30, 31, via the circumference 34, 34′,supports the harness elements against backward movement.

The rotational movement of the guide roller may be continuous orcontrolled in a specific manner by means of control and monitoringelements. In the case of continuous movement, the position of therecesses 13, 33 give rise to periods of time in which the ejectors 24,25 can eject the harness element 16. However, the movement of the guideroller may also be governed by the conveying member 21, so that theguide roller waits in a position according to FIG. 3 until the ejectors24, 25 have performed their task. The guide roller then executes acomplete revolution as quickly as possible, in order to return to theposition according to FIG. 3. In this case, the guide roller may bedriven by means of a DC motor or a stepping motor. Corresponding rotarytransducers have to be provided for monitoring the position. In anyevent, however, the drive 7 is operatively coordinated with the drive ofthe ejectors 24, 25, as can be gathered from the manner of operationdescribed.

What is claimed is:
 1. A device for the transfer of harness elements from a conveying member, in a drawing-in machine for warp yarns, onto at least one carrying member of a weaving machine that has an ejector for removing the harness elements from the conveying member, the device comprising a guide roller for the harness elements which is mounted rotatably about an axis and which has guides for the carrying member which guide the carrying members in two orthogonal directions.
 2. A device according to claim 1, wherein the guide roller has a recess that starts from the circumference and extends towards the axis.
 3. A device according to claim 2, wherein the recess has a boundary which acts as a guide surface on the guides to propel the harness elements forward.
 4. A device according to claim 3, wherein the guide roller has a plurality of recesses for propelling a plurality of carrying members next to one another.
 5. A device according to claim 1, wherein the guide roller has a plurality of guides for guiding a plurality of carrying members next to one another.
 6. A device according to claim 2, wherein the recess of the guide roller together with the carrying member form a transfer lock for the harness elements.
 7. A device according to claim 1, wherein the guide roller is arranged proximate to one end of the carrying member.
 8. A device according to claim 1, wherein the guide roller has a first drive which is adapted to be operatively coordinated with a second drive that drives the ejectors. 